Morning Glory or Koali'awa
Ipomoea indica

This indigenous vine comes from the Convolvulaceae family and can be found on all the main Hawaiian Islands. The leaves are heart shaped. The flower opens blue in the morning and changes to pink later in the day. Ancient Hawaiians pounded the stems and roots and used them externally to treat bruises and broken bones and was very dangerous if taken internally.

 
The koali'awa was used as a medicinal plant by ancient Hawaiians.